The invention relates to automatic control systems for public washroom fixtures such as faucet valves, soap dispensers, electric dryer switches, and the like.
There is a recognized need for sanitary public washroom controls that avoid the need for members of the public to physically touch lavatory faucet valve handles, paper towel dispensers, electric hand dryers, soap dispensers, urinal flush valve handles, and the like. There is also a recognized need to maximize conservation of water in public washrooms by preventing faucets from being left open. Various sensors are known which sense the presence of a person's hand beneath a lavatory faucet to automatically turn on the water for a set interval without the need for the person to physically touch a control handle. Generally, each such sensor is directly linked to a water valve, soap valve, or the like. Patents 4,914,758 and 5,031,258, assigned to Bauer Industries, Inc., are believed to be representative of the state-of-the-art. Actuation of a large number of solenoid valves in some instances consumes more power than is desirable. Use of multiple solenoid valves in some cases is costly enough that it would be desirable to reduce the number of solenoid valves.
Accordingly, there is a unmet need for a relatively inexpensive, easily installed control system which automatically senses the presence of a person at a wash basin or urinal and automatically opens faucet valves, soap dispenser valves, turn on hand dryers, etc., and which minimizes power consumption in battery-powered systems, prevents water valves from remaining open due to battery failure, and produces an alarm indicating a low charge battery condition.